duckworth



UNITE S ATES FICE.

C. DUCKWORTH, OF HARTFORD, CONNECTICUT.

LOCK.

Specification of Letters Patent No. 25,959, dated November 1, 1859.

To all whom 'it may concern:

Be it known that I, C. DUCKWORTH, of Hartford, in the county of Hartford and State of Connecticut, have invented a new and Improved Lock; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings, making a part of this specification, in which- Figure l, is a view of the interior of the lock, in a locked state, the side of the case nearest the eye being removed. Fig. 2, an inverted plan of ditto with the lower side of the case removed and the lower part of arm D, bisected as indicated by the line x, m, Fig. l. Fig. 3, a perspective view of the ke Similar letters of reference indicate corresponding parts in the several figures.

The object of this invention is to obtain a simple, economical and secure lock, one that may be opened with facility in a legitimate way and still be unpickable or proof against burglars.

The invention consists in the employment of a series of tumblers arranged with a slotted arm attached to the bolt and used in connection with a key of peculiar construction the whole being arranged as hereinafter described to effect the desired end.

To enable those skilled in the art to fully understand and construct my invention, I will proceed to describe it.

A represents the case of the lock which may be of rectangular or other proper form.

B, is the bolt fitted in the case A, as usual and having a spring C, bearing on its upper surface to prevent its casual movement.

To the bolt B, a pendent arm D, is attached. This arm D, is slotted transversely at equal distances apart, the slots a, being parallel with each other with horizontal projections b, between them.

E, represents a series of tumblers which work on fulcrum rods c. Any proper number of tumblers may be used. Nine are shown in the drawings, there being three fulcrumed pins, with three tumblers on each pin. The tumblers E, are of varying lengths, in Fig. Qwone long and two short tumblers are shown in the uppermost row.

The front ends of the shorter tumblers E, where the lock is in a locked state, rest on the projections and against shoulder o', but the front ends of the long tumblers are just within the slots a. It will be seen therefore that in order to throw back the bolt B the short tumblers E, must be brought` in line wth the slots a, and the bolt B, may then be shoved back, the tumblers E, allowing the arm D, to pass back on the tumblers. This adjustment of the tumblers is effected by the key F, the bit CZ, of which is corrugated or fluted at one side, as shown at e, Fig. 3. The corrugations c, when the key is fitted in the lock, and turned so that the prominences will act upon the back ends of the tumblers, will actuate the short tumblers so as to bring them above the shoulders b, and in line with the slots a and allow the bolt to be shoved back. In order to prevent the long tumblers being acted on by the bit (Z, said bit is recessed at proper points as shown at z', in Fig. 3.

The bolt B, has the upper end of a lever G, connected with it. The fulcrum of this lever is at y', and the lever extends down back of the tumblers E, as shown clearly in Fig. l.

To the shank of the key F, a lever H, is attached as shown clearly in Fig. 3. This lever H, extends down nearly to the end of the key and is intended to actuate or throw back the bolt B, when the tumblers E, have been adjusted in line with the slots a in the arm D, by the corrugations of the bit cl. The lever H, may be readily actuated by the thumb when the tumblers are properly adjusted to permit the bolt to be thrown back.

It will be seen that the long tumblers render the device complex for if a person attempts to pick the lock there is no means of ascertaining which tumblers require adjusting. The tumblers may also be arranged differently on their fulcrum pins so as to constitute changes. This would be necessary in case of the loss of a key, and also in case of a change of employees who may possess a knowledge of the construction of the lock and the position of the tumblers. The lock may be very cheaply constructed and there are no parts liable to become deranged by use. l

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is-

The tumblers E, slotted arm D, attached to the bolt B, lever G, or its equivalent and the key F, provided with lever H, combined and arranged substantially, as and for the purpose set forth.

C. DUCKWORTH.

IVitnesses Ci-ras. E. PERKINS, CHARLES VHITTLESEY, 

